About RunBikeCalc

Our Mission

RunBikeCalc provides free, accurate, and easy-to-use calculator tools for runners, cyclists, and endurance athletes. Our mission is to support your training goals with scientifically-based calculations that help you train smarter and perform better.

Hi, I'm Glen

Glen cycling in Colorado mountains

I'm an avid cyclist and endurance athlete: I completed my first Ironman 70.3 in 2025 and I've been hooked on data-driven training ever since. I built RunBikeCalc because I couldn't find all the tools I needed in one place.

Whether I was calculating my Zone 2 heart rate for base building, figuring out my FTP for power-based workouts, or planning race pacing strategies, I was constantly bouncing between different websites with inconsistent formulas. It was frustrating. So I decided to build something better.

Every calculator on this site has been personally tested through my own training. I use these tools every week: they're not theoretical, they're practical. I've refined them based on real-world feedback from athletes at every level, from people just getting off the couch to competitive racers chasing PRs.

My goal is simple: give you free, accurate tools that actually help you train smarter. No subscriptions, no paywalls, no BS. Just the calculations you need to get faster and stay healthy.

A quick note on how I keep the lights on: Some of the product links in my gear guides are affiliate links. If you buy something through one of those links, I earn a small commission at no extra cost to you. I only recommend gear I've actually used or thoroughly researched: I'm not going to shill junk just to make a buck. These commissions help me keep the calculators and training plans completely free. Thanks for the support!

Why Choose RunBikeCalc?

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Always Free

All our calculators are completely free to use with no registration required.

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Mobile Optimized

All tools work perfectly on your phone, tablet, or desktop device.

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Science-Based

Our calculations use proven scientific formulas and methods.

Get Started

Ready to optimize your training? Explore our calculator tools and start training smarter today.